Headliners comprising large openings meant to cover roofs provided with a transparent portion, such as a sunroof or a panoramic roof, require reinforcement in the opening area to maintain the rigidity of the headliner.
The use of metal reinforcement frames for this purpose is known.
To reduce weight, particularly when the opening corresponding to the transparent portion has large dimensions, the replacement of metal frames with plastic frames is known.
However, plastic materials have a high coefficient of expansion compared to metals. Consequently, plastic frames have drawbacks related to the appearance of deformations due to thermal loads, an effect that is particularly significant in the vehicle roof, which is exposed to high temperatures.
In order to minimise said deformations, document EP2305517 is known, disclosing a reinforcement segmented into several portions, as the deformation is proportional to the length of the segments that form the reinforcement. However, the drawback of this solution is that it is complex, particularly with regard to the assembly thereof on the headliner.
Thus, the aim of the invention is to maintain the weight reduction of the headliner using a plastic frame while preventing the deformation of the plastic frame and consequently of said headliner, by the use of a reinforcement with a simple construction and assembly.